1. Field of the Invention
The present invention relates to a conductivity test jig, a conductivity test apparatus, and a method of testing conductivity.
2. Description of the Related Art
Conventionally, quality of a wiring harness is judged by testing conductivity between terminals, wherein the wiring harness includes a plurality of electric wires and terminals attached to ends of the electric wires, and connectors receiving the terminals.
Conventionally, a method of testing conductivity of such a wiring harness includes steps described below. Firstly, one of the terminals of the wiring harness is selected, and a voltage is applied to the one terminal, then, voltages of other terminals are measured. Voltage is applied to all the terminals sequentially, and in each case, voltages of the other terminals are measured sequentially. Thus, mutual conductivity conditions of all the terminals are figured out.
By comparing the measured mutual conductivity conditions of the terminals with the mutual conductivity conditions of the terminals of a normal wiring harness, the quality of the wiring harness is judged, and a trouble point is detected.
For testing conductivity of the wiring harness, various conductivity test jigs are used (for example, see Patent Document 1). The conductivity test jig disclosed in Patent Document 1 includes: a jig main body to receive a connector and having a hole opened on an outer surface; a rotating piece rotatably mounted on the jig main body; and a solenoid.
A conductivity pin is projected in an interior of the hole of the jig main body. The conductivity pin is inserted into a through hole formed in the jig main body, and into a compression coil spring which is inserted into the through hole. The conductivity pin is pushed toward the hole by the compression coil spring, and provided projectably and retractably from the through hole.
An end of the rotating piece is formed in a hook shape. The rotating piece is rotatable between a position where the end is projected into the hole and a position where the end is removed from the hole. The solenoid includes: a solenoid main body attached to the jig main body; and a rod projectably and retractably mounted on the solenoid main body.
When a conductivity test is carried out using the above described conductivity test jig, firstly, the connector is inserted into the hole to make the terminal of the connector contact the conductivity pin, and the connector is pushed into the conductivity test jig. Then, the terminal resiliently deforms the compression coil spring and the conductivity pin is partially inserted into the through hole. Under this condition, the solenoid rod is extended and the end of the rotating piece is projected into the hole to keep the connector in the hole, then the conductivity test is performed.
After the conductivity test ends, the solenoid rod is contracted to release the end of the rotating piece from the hole. Then, due to the resilient force of the compression coil spring, the conductivity pin pushes up the terminal of the connector, and the connector is released out from the hole.
The conductivity test jig as such is projectingly attached to a rear wall (a lower wall) of a wiring board on a surface of which the wiring harness is wired. Therefore, compared with a conductivity test jig which is attached to a front wall of the wiring board (See Patent Document 2), This conductivity test jig prevents the connector or the wiring harness from being damaged by interfering with the conductivity test jig, and good workability is provided because the electric wire may not be hooked on the conductivity test jig.
Further, because such a conductivity test jig moves perpendicular to the wiring board, when a plurality of connectors are massed at a part of the wiring harness, and a plurality of conductivity test jigs corresponding to the connectors are attached to the wiring board, each conductivity test jig is not interfered with the other conductivity test jigs when they are moving, and conductivity test is performed effectively.    [Patent Document 1] Japanese Published Patent Application No. H05-288792    [Patent Document 2] Japanese Published Patent Application No. H07-37448
However, according to the conductivity test jig described in Patent Document 1, the connector is pushed into the hole to make the terminal of the connector contact the conductivity pin so that the compression coil spring is resiliently deformed. Further, after the conductivity test ends, the conductivity pin pushes up the terminal to push the connector out of the hole. Therefore, there is a problem that the terminal and the conductivity pin are burdened, and the terminals and the conductivity pin may be deformed or damaged. Further, because the connector is pushed so that the connector is inserted into the hole, workability is not good.
Accordingly, an object of the present invention is to provide a conductivity test jig to test in which the terminal and the conductivity pin are not burdened so much, and a connector can be easily detachably attached to the conductivity test jig, and to provide a conductivity test apparatus having the conductivity test jig, and a method of testing conductivity.